Glossary

Breakdown of complex organic substances into simpler molecules or ions by physical, chemical and/or biological processes.

Human-induced conversion of forested land to nonforested land. Deforestation can be permanent, when this change is definitive, or temporary when this change is part of a cycle that includes natural or assisted regeneration.

Land in a state that results from persistent decline or loss of biodiversity and ecosystem functions and services that cannot fully recover unaided.

Reduction of nitrates and nitrites to nitrogen by microorganisms.

Desertification means land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities. Desertification does not refer to the natural expansion of existing deserts.

See "driver".

The transformation of information from coarser to finer spatial scales through statistical modelling or spatially nested linkage of structural models.

In the context of IPBES, drivers of change are all the factors that, directly or indirectly, cause changes in nature, anthropogenic assets, nature’s contributions to people and a good quality of life.

• Direct drivers of change can be both natural and anthropogenic. Direct drivers have direct physical (mechanical, chemical, noise, light etc.) and behaviour-affecting impacts on nature. They include, inter alia, climate change, pollution, different types of land use change, invasive alien species and zoonoses, and exploitation.
• Indirect drivers are drivers that operate diffusely by altering and influencing direct drivers, as well as other indirect drivers. They do not impact nature directly. Rather, they do it by affecting the level, direction or rate of direct drivers.
• Interactions between indirect and direct drivers create different chains of relationship, attribution, and impacts, which may vary according to type, intensity, duration, and distance. These relationships can also lead to different types of spill-over effects.
• Global indirect drivers include economic, demographic, governance, technological and cultural ones. Special attention is given, among indirect drivers, to the role of institutions (both formal and informal) and impacts of the patterns of production, supply and consumption on nature, nature’s contributions to people and good quality of life.

Drylands comprise arid, semi-arid and dry sub-humid areas. The term excludes hyper-arid areas, also known as deserts. Drylands are characterised by water scarcity and cover approximately 40 % of the world's terrestrial surface.

Downscaling based on mechanistic models, which may be more appropriate than statistical downscaling in systems where the relationship between coarse scale and fine scale dynamics are complex and non-linear, or observational data are insufficient.

See "models".